Napa River Ecological Reserve: An Oasis in the Heart of the Wine Country

By Teresa LeBlanc

A very special place lies within the wine-growing region of the Napa Valley. Surrounded by vineyards, the 73-acre Napa River Ecological Reserve (NRER) retains a remnant of riparian forest, with both an ecological and historical perspective. Just east of the town of Yountville and minutes from the Central Coast Region office, NRER is the last sizable section of riparian vegetation left in the Napa Valley and provides habitat for approximately 150 species of birds, numerous butterflies and various mammals. It also supports a diversified plant community of 238 plants, including the federal and state endangered Sebastopol meadowfoam (Limnanthes vinculans).

A human community of private and public owners gives NRER a one-of-a-kind story. Its riverine components brought it statewide attention, and the Wildlife Conservation Board purchased the Napa River Ecological Reserve in 1976. Since more than 90 percent of California riparian habitat has disappeared, the Fish and Game Commission gave it ecological reserve status to protect these plant communities. NRER has a long human history, dating from when the native Wappo tribe used it as a hunting and gathering area. Later, these riverside woodlands became part of George C. Yount's Mexican land grant, "Caymus Rancho" in 1836. The present location of the Yountville Cross Road, the southern boundary of NRER, also served as the southern perimeter of Yount's 11,900-acre holding. During the years 1858 through 1879, annual church gatherings took place with an estimated 4,000 people in attendance, within an open grassy area known as the "Yountville Campgrounds." These participants brought cattle, chickens, sheep and other livestock to sustain their stay. Many brought their own camping equipment; those who didn't borrowed materials for tent cabins from local merchants. The last organized religious gathering took place in 1974, while the property was still in private ownership. That gathering site is located in the interior portion of NRER, just off the trail where you can find a small bench facing the area.

Instead of grazing cattle and campfires, resident acorn woodpeckers swoop from oak to oak, nesting communally or defending territory. Follow them with your eyes as they fly to "granary trees." These are storage places, usually within snags or dead limbs in which the woodpeckers have drilled holes and placed their collected acorns. At times, the acorns themselves may attract predatory insects that offer opportunistic foraging by the birds. Other species like the Stellar's and western scrub jays bury acorns in the fertile soil litter. When these acorns go unretrieved, the birds' benign neglect is NRER's gain: the acorns grow long tap roots, generating future oak trees. Another avian seed collector, the white-breasted nuthatch, caches seeds within the oak's rough bark and branches. Its sharp, curved claws help it move about the tree and around limbs, challenging gravity as it searches for food. Overall, the oaks provide many elements critical to NRER's aerial inhabitants.

Hosting resident, wintering and fall migrant species, NRER is well known to birders from as far away as Europe. The warm summer months typically attract locals with the cooler temperatures vegetation and hydrology provide. The Napa River flows through the area, supplemented by Conn and Rector creeks. Conn Creek was dammed to create Lake Hennessey, which is part of City of Napa's water supply. By late summer, it typically does not have visible flows but does support various species of willow trees that may reveal a Wilson's warbler, or Annas' and Allen's hummingbirds in the spring.

Large valley and coast live oaks and California bay trees dominate NRER. Some valley oaks have been aged between 250 to 280 years. Many are mantled with grayish-green lace lichens, which are not actually plants but a symbiotic combination of fungus and algae. Several species of willow including sandbar, polished and arroyo, are found along the banks and provide important habitat for insects, birds and necessary shade elements for fish. Other trees include white alder, Fremont's cottonwood and Oregon ash. Wild rose, common snowberry, Santa Barbara sedge, poison oak and both native and non-native blackberries primarily compose the understory. Large, twisting native grapevines (Vitis californica) wrap sinuously around the larger trees.

The word "riparian" alone cannot describe the diversity of the Napa River Ecological Reserve. This riparian habitat ranges from oak woodland, grassland and swale-type habitats. Given the structure and ecological aspects of riparian vegetation it's no wonder that approximately 70 species of birds nest within NRER including the yellow-breasted chat, a Department of Fish and Game (DFG) "Species of Special Concern." The area is accessible during late spring, summer and fall seasons. With high seasonal rainfall, the river may rise and inundate NRER's interior during the winter. It is a natural cycle, given the vegetation is well adapted to flooding and gives NRER a well deserved rest. At times, during El Niño years, the river has breached its western levee, imprinting a high-water mark evident within the lower canopy.

NRER remains a place where communities converge. It draws a large following in terms of its public and wildlife use. Although owned and managed by the DFG, NRER has welcomed assistance from public agencies, non-profit organizations and private citizens. Management activities focus primarily on habitat conservation, exotic vegetation control and managing public use. Through a cooperative agreement, Napa County Public Works helps with the maintenance of the area by picking up accumulated trash within the small parking lot area and provides assistance with special projects. It remains the responsibility of visitors to pack out what they pack in. In 1989, Napa's Jared Young Boy Scout Troop built a footbridge to help the public access NRER's interior portion. A small oak restoration project receives the support of local school children, while educating them about conservation and the importance of land stewardship. Recently, a kiosk was installed to help educate the area's visitors about its unique resources. The project was funded by a cooperative federal grant through "Partnerships for Wildlife," a three-party grant program with participation from the U.S. Fish and Wildlife Service, National Fish and Wildlife Foundation and DFG. The local Napa-Solano Audubon Chapter helped fund the project as well as produce brochures on NRER's plants, birds and butterflies with a local grant. (The various brochures are available from DFG's Central Coast Regional office or may be found on-site in limited quantities.) They also have been instrumental in re-establishing the one-mile interpretive loop trail and its companion trail guide. The pedestrian trail is maintained annually by the Department of Forestry and Fire Protection and Department of Corrections inmate fire crews.

Whether you are birdwatching, hiking, fishing or just appreciating a piece of local history, the Napa River Ecological Reserve is a worthwhile visit. NRER continues to provide an opportunity to showcase the state's overall natural diversity, and to educate visitors about the importance of riparian habitats.